Conventionally, there has been a separate-type air conditioner disposed with a heat source unit, a utilization unit, and a liquid refrigerant communication pipe and a gas refrigerant communication pipe that interconnect the heat source unit and the utilization unit. In this air conditioner, a method is employed where the heat source unit is filled in advance with a predetermined quantity of refrigerant, and at the time of local installation, the refrigerant circuit whose refrigerant quantity is insufficient depending on the lengths of the liquid refrigerant communication pipe and the gas refrigerant communication pipe that interconnect the heat source unit and the utilization unit is filled with additional refrigerant. However, because the lengths of the liquid refrigerant communication pipe and the gas refrigerant communication pipe that interconnect the heat source unit and the utilization unit differ depending on the situation of the locality where the air conditioner is installed, sometimes it has been difficult to fill the refrigerant circuit with an appropriate quantity of refrigerant.
In order to counter this problem, there is an air conditioner disposed with a function which, during test operation after local installation, performs cooling operation such that the degree of superheating of the refrigerant evaporated in a utilization heat exchanger becomes a predetermined value, detects the degree of subcooling of the refrigerant condensed in a heat source heat exchanger, and judges from the value of this degree of subcooling whether or not the refrigerant circuit is filled with an appropriate quantity of refrigerant (e.g., see Japanese Patent Publication No. 62-158966).